I bought an emachines computer with 400GB hard drive and Vista installed. I used gparted to reduce the Vista partition to 80GB. Then I successfully added Simply Mempis and Ubuntu with grub allowing me to boot any of them.Next I wanted to add pclinuxos gnome 2.12.2. The live CD loaded and worked well. I then tried to install it on a new partition and everything went well until I got to the installation of the boot loader. Somehow this step wiped out my hard drive completely.

At this point I reinstalled Vista on its original partition and wanted to install pclinuxos next in case it wiped out the hard drive again. The response to install was that there was no place to install it. I then went to gparted which showed the whole disk unallocated, not seeing the Vista partition.

How do I get back to where I was before pclinuxos wiped out my hard drive?

Use gparted to wipe out the Vista partition - set up all the partitions (using gparted/parted/cfdisk ...whatever) from Linux before installing anything.
Vista (on a clean install) allocates partitions differently - even XP doesn't (or didn't when I tested) like it. Preallocate the partitions first and everyone will behave.

Using smart fdisk, I have restored the system partially. I can dual boot a form of Vista and pclinuxos. I called technical support for my computer and described my problem. I was told that I will need a recovery disk which they will send me. The problem seems to be that one of the needed files, mscories.dll, was lost and is not available on the disk that comes with the computer.